Question: Who was the Chairperson of United Russia beginning on January 1, 2001?
Paraphrase: Who was Russia's chairperson on 1/1/2001?
SPARQL (Wikidata): SELECT ?obj WHERE { wd:Q151469 p:P488 ?s . ?s ps:P488 ?obj . ?s pq:P580 ?x filter(contains(YEAR(?x),'2001')) }